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SELF AND RUEUS E. HITCHCOCK, CE SAME PLACE.

Letters Patent 1Y0. 98,180, dated December 2l, 1869.

METHOD 'OF HEADING- SCREWS.

v-Ovh- The Schedule referred to in these Lettera Patent and making part o f theaame.

To all whom it may concern f Be it known' that, I, DANIEL T. MUNGER, of Wa` terbury, in the county of New Haven, and State of Connecticua-have invented a new Improvement in Method of Heading Screws and Rivets; and I do hereby declare the following, when 'taken in connection with the :accompanying drawings, and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this speciiicatiou, and represent,

Figure 1, a side view of the screwor rivet complete; Figure 2, the shank; Figure 3, the disk; Figure 4, the shank, as placed through the disk, preparatory to the introduction ofthe dies and in Figure 5, a central section of the head, illustrating the manner iu which the parts are united together.

Figure (i, a sectional view of thedies,with the blank placed therein, preparatory to striking up.

v This invention relates to au improvement in screws, such as are used for saw-handles, but is alike applicable to the formation ot' other screws, rivets, 85e.

Heretofore, saw-screws have been either formed cntire from cast-metal, or the head soldered to the shank ofthe screw. Both constructions are liable to break, inasmuch as the cast-metal or soldering is not suicientl y strong to withstand the strain upon the saw, Aand this diiiiculty exists in screws, rivets, Sto., for other purposes.

By my invention,itliese diiiicultiesare entirely overcome, and consists in forming a perforated disk as a blank for the head, and in a blank foi` the shank, the

said shank being previously upset, so asto form a small head, and conioally-shaped neck, then setting the said formed shank through the perforation in the disk, then placing both disk and shank int-o suitable' dies, then driving thc shank through the disk until the head on the shank is embedded into the disk, and the disk driven into the dies, .so that that part of the disk immediately below the head of the shank cong tracts closely around the neck ofthe shank.

A,`fig. 3, is the blank for the head, which consists of a disk struck from sheetanetal, and perforated through its centre. l

B, tig. 2, is the blank for the shank, formed from wire, its head-end upset, so as to enlarge the blank at that end, and form a small head and conically-shaped neck, the shoulder at the head being slightly rounded; then this shank is inserted through the disk, as in g,

4, and placed in suitable dies. Theshank is driven down through the disk, and the disk and shank into the die, which process unites the two parts, as seeniu tig. 5.

This result is practically demonstrated by cutting open many of the heads, which are found to be the same, and this union of the two'parts is the strongest possible to be made, inasmuch as, in striking up, the metal is hardened or condensed Iabout the head and neck. The shank is threaded in the usual manner.

I claim, as my invention- The method herein described, of making blanks for screws, rivets, and'like articles of manufacture.

. DANIEL T. MUNGER. Witnesses: Ennis BALDWIN, J. W WEBSTER. 

